Quality of life assessment: WHOQOL-BREF

To assess quality of life, we used the WHOQOL-BREF (World Health Organization Qualify Of Life) questionnaire, which is a shortened version of the WHOQOL-100 instrument developed by the World Health Organization. The WHOQOL-BREF Brazilian version was developed and validated by Fleck et al. [40, 41]. It contains 24 questions in four domains: physical, psychological, social relationships and environment. There are also two additional questions that are intended to be examined separately: Question 1 asks about an individual’s overall perception of his or her QOL (quality of life), and question 2 asks about an individual’s overall perception of his or her own health. The items were rated on a 5-point Likert scale. For the first and second questions, the scale ranged from very poor = 1 to poor = 2, neither poor nor good = 3, good = 4 and very good = 5. For other questions, the scale ranged from not at all = 1 to a little = 2, a moderate amount = 3, very much = 4 and extremely = 5. Some items (3, 4 and 26) were recoded so that the values were inverted (5 = 1, 4 = 2, 3 = 3, 2 = 4 and 1 = 5). We followed the WHOQOL-BREF scoring guideline to score missing data in the questionnaire.

Domain facets incorporated within domains were as follows: (1) physical health related to activities of daily living, dependence on medicinal substances and medical aids, energy and fatigue, mobility, pain and discomfort, sleep and rest and work capacity; (2) psychological bodily factors related to image and appearance, negative or positive feelings, self-esteem, spirituality/religion/personal beliefs, thinking, learning, memory and concentration; (3) social relationships related to personal relationships, social support and/or sexual activity; and (4) environment, financial resources (related to freedom, physical safety and security), health and social care (accessibility and quality), home environment, opportunities for acquiring new information and skills, participation in and opportunities for recreation/leisure activities, physical environment (pollution/noise/traffic/climate) and/or transport.